Compact Disc subcode
（重定向自Subcode）
Subcode or subchannel data (called "control bytes" in the CD-ROM specification) refers to data contained in a compact disc (CD) in addition to digital audio or user data, which is used for control and playback of the CD. The original specification was defined in the Red Book standard for CD Digital Audio, though further specifications have extended their use (including the CD-ROM, CD Text and CD+G specifications).